Bio-inspired needle for controlled release

Abstract

A micro-needle (MN) patch is formed as an array of 3-D bioprinted structures having a relatively hard planar base with multiple water sensitive barbed tips extending therefrom. The barbed tips are formed from a polymer material configured to exhibit reversible shrink-swell volume change in response to surrounding humidity to facilitate skin penetration under the shrinkage conditions and long-term adhesion when swelling in skin tissues.

1 . A microneedle (MN) patch, comprising:
 a 3-D bioprinted structure comprising:
 a substantially planar base formed from a first photocrosslinkable hydrogel material; and 
 water-sensitive barbed structures formed from a second photocrosslinkable hydrogel material printed onto and extending substantially perpendicular from a surface of the base, the barbed structures each having a volume configured to reversibly shrink and swell in response to surrounding humidity, wherein the barbed structures have a hardness configured to penetrate live skin tissue. 
   
     
     
         2 . The MN patch of  claim 1 , wherein the first photocrosslinkable hydrogel material comprises a polyethylene glycol diacrylate (PEGDA) gel. 
     
     
         3 . The MN patch of  claim 1 , wherein the second photocrosslinkable hydrogel material comprises a mixture of PEGDA and methacrylated hyaluronic acid (HAMA). 
     
     
         4 . The MN of  claim 3 , wherein the mixture comprises from 2.5% to 7.5% HAMA and from 7.5% to 20% PEGDA. 
     
     
         5 . The MN of  claim 3 , wherein the mixture comprises 7.5% HAMA and 7.5% PEGDA. 
     
     
         6 . The MN of  claim 1 , wherein the base further comprises graphene oxide (GO), wherein the GO is configured to heat in response to exposure to near infrared (NIR) light. 
     
     
         7 . The MN of  claim 1 , wherein the second photocrosslinkable hydrogel material further comprises thiolated heparin (Hep-SH). 
     
     
         8 . The MN of  claim 1 , wherein the second photocrosslinkable hydrogel material further comprises a drug configured for transdermal delivery. 
     
     
         9 . The MN patch of  claim 1 , wherein the barbed structures are printed in layers to define alternating layers of radially-extending barbs along a height of each barbed structure. 
     
     
         10 . The MN of  claim 1 , wherein the first photocrosslinkable hydrogel material and the second photocrosslinkable hydrogel material are configured to polymerize in response to exposure to light within a wavelength range of 365 nm to 405 nm. 
     
     
         11 . A microneedle (MN) patch for transdermal drug delivery, comprising:
 a substantially planar base 3-D bioprinted from a first bioink solution; and   water-sensitive barbed structures 3-D bioprinted from a second bioink solution onto and extending substantially perpendicular from a surface of the base, the barbed structures each having a volume configured to reversibly shrink and swell in response to surrounding humidity, wherein the barbed structures have a hardness configured to penetrate live skin tissue.   
     
     
         12 . The MN patch of  claim 11 , wherein the first bioink solution comprises a polyethylene glycol diacrylate (PEGDA) gel. 
     
     
         13 . The MN patch of  claim 11 , wherein the second bioink solution comprises a mixture of PEGDA and methacrylated hyaluronic acid (HAMA). 
     
     
         14 . The MN of  claim 13 , wherein the mixture comprises from 2.5% to 7.5% HAMA and from 7.5% to 20% PEGDA. 
     
     
         15 . The MN of  claim 13 , wherein the mixture comprises 7.5% HAMA and 7.5% PEGDA. 
     
     
         16 . The MN of  claim 11 , wherein the first bioink solution further comprises graphene oxide (GO), wherein the GO is configured to heat in response to exposure to near infrared (NIR) light. 
     
     
         17 . The MN of  claim 11 , wherein the second bioink solution further comprises thiolated heparin (Hep-SH). 
     
     
         18 . The MN of  claim 11 , wherein the second bioink solution further comprises a drug configured for transdermal delivery. 
     
     
         19 . The MN patch of  claim 11 , wherein the barbed structures are printed in layers to define alternating layers of radially-extending barbs along a height of each barbed structure. 
     
     
         20 . The MN of  claim 11 , wherein the first bioink solution and the second bioink solution are configured to polymerize in response to exposure to light within a wavelength range of 365 nm to 405 nm.